Patent GB-190417017-A (GB)
Title: Improvements in Electric Motor Control Systems
Filed: 1904-08-03
Granted: 1905-06-22
Abstract: 17,017. British Thomson-Houston Co., [General Electric Co.]. Aug. 3. Motors, controlling.-A controller consists of a magnet winding with a number of armatures, each being attached to a separate switch arm, the arrangement allowing of the connection of two motors in series or parallel with varying resistance and also of reversal of the motors. The controller is an improvement on that described in Specification No. 3886, A.D. 1904. Fig. 2 shows the switches arranged for a multiple-unit train-control system. The coil C is provided with a number of armatures controlling three sets of switches. The armatures of the first set, f <1> to f<4> and b<1> to b<4>, are arranged to connect the motors for forward or backward rotation, the second set s<1>, sand p, p<1> to connect the motors in series or in parallel, and the third set r' to r<8> to control the amount of resistance R in the circuit. When the current flows through the coil C, the armatures are attracted and tend to close the switches, some of which are prevented from closing by cams on the shafts I, J and sleeve K. The coil D controls the shaft I and cams i<1> to i<4>. The coil O controls the shaft J and cams j<1> to j<4>, and the coil P controls the sleeve K. The coils C, D, P, and O are connected to the train wires 1, 2, 3, and 4. Two master-controllers A, A' have four positions for each set of movable contacts for forward and backward rotation. When the master-controller A is moved to its first position for forward rotation, circuit is completed from the trolley T to the contacts a<1>, a<3>, train wire 1, bridging-piece d<2> to coil C, contacts 30, and bridging-piece n to earth E. The coil C then tends to close the switches, some not being allowed by the cams to move, and only the switches f<1> to f<4> and s, s<1> being closed. This completes the motor circuit from the trolley T to the contact 13, switch s, through the upper resistances R, the contact 8, switch f<4>, switch b<3>, armature of the motor M', switch b<4>, switch f<3>, contact 7, field of motor M', coil t, contact 24, switch s', lower resistances R, contacts 16, 6, switch f<2>, switch b<1>, armature of motor M, switch b<2>, switch f<1>, contact 5, and field of motor M to earth. The two motors are thus in series with all the resistance. The next position of the master-controller puts in the circuit the coil O, the core of which breaks the circuit at L, when the core drops and completes the circuit, and is drawn up again. The core thus has a reciprocating movement, and turns the shaft J by a toothed wheel H and pawl h. The cams j<1> to j<4> rotate with the shaft, allowing other switches to close, cutting out the resistance, and a pin h<2> then engages the pawl h<1> and holds up the core. The coil t may be arranged to open the circuit of the coil O and stop the cutting out of resistance when a certain current value is reached. With the master-controller in its third position, the coil P draws up its core, the arm N thus connecting the two contacts 31, when the arm N' rises and connects the contacts 30, while the switches p, p' close. The two motors are then in parallel, and all the resistance is in the circuit. The fourth position of the master-controller cuts out the resistance. Backward rotation is obtained by working on the side b of the controller, causing the switches b<1> to b<4> to close instead of f<1> to f<4>, the other arrangements remaining as for forward rotation.